$\dfrac{2}{3} + \dfrac{9}{10} = {?}$
Answer: ${\dfrac{2}{3}}$ ${\dfrac{9}{10}}$ $+$ ${\dfrac{2 \times 10}{3 \times 10}}$ ${\dfrac{9 \times 3}{10 \times 3}}$ $+$ ${\dfrac{20}{30}}$ ${\dfrac{27}{30}}$ $+$ $ = \dfrac{{20} + {27}}{30} $ $ = \dfrac{47}{30}$